Enemy (and other super mysterious and freaky unexplainable films)

Just finished watching Jake Gyllenhaal's Enemy. Denis Villeneuve, the director, seems to be channelin the ghosts of Alfred Hitchcock and Stanley Kubrick. When is the viewer watching a nightmare and when are they watching some inexplicable tear in the fabric of the film's dimension allowing fantastical monsters into the fictional realist based universe?

Like Under the Skin (2013), nothing is really explained. Motivations are cleared up. But wow! What a gut punch of a ride. Disturbing to say the least. These films (on paper or if the filmmaker pitched the story to you, the potential studio head) shouldn't work.

Inception (a very famous example of a twist ending that could go either way) has an ambiguous ending but at least many of the questions asked throughout the film were covered. So, does the Life of Pi. They have plenty of fantastical elements but they are not the film's I'm talking about.

What other freakishly Lynchian, surreal existentially horror films have left you disturbed at the end, yet still satisfied for watching despite the lack of answers?